Graduation Date

Summer 8-14-2015

Document Type


Degree Name

Master of Science (MS)


Medical Sciences Interdepartmental Area

First Advisor

Stephen J. Bonasera

Second Advisor

Lani Zimmerman

Third Advisor

Bunny Pozehl


Numerous important health outcomes directly relate to one's ability to maintain normal gait speed. The purpose of this study is to employ ubiquitous smartphone technology, using algorithms developed and validated by our lab in a controlled setting, to continuously and noninvasively measure aspects of subject health status, including step counts, gait speed, and activity level, in a naturalistic community setting. A total of 33 ambulatory, independently dwelling older adults were recruited from Nebraska Medicine, including 22 healthy control and 11 frail individuals. Clinical performance measurements of frailty (4MW, TUG, F8W) and validated survey responses (LLFDI, SAFFE, PROMIS) were compared to our smartphone based metrics collected in the community over 24-hours. We identified significant differences between control and frail subjects in percent activity (p